A blonde walks into a store and asks the helper if she could buy this

A blonde walks into a store and asks the helper
If she could buy this tv the helper sees
No we don't sell to blondes
And so the blonde goes
And dies her hair red
And goes back and asks the same helper
If she could buy the tv
And the helper said once again
No we do not sell to blondes so the blonde goes
And dies her hair brown
And goes back to the same helper
And asks one again if she could buy the tv
And once again the helper said
No we do not sell to blondes and the blonde sees
How do you know i'm blonde?
And the helper sees becuz that's not a tv
It's a mirror